The first time I came across this in Chicago, occurred right at the point in time where the record industry was breathing it last breath. All of the record retailers were heavily discounting almost all of their inventory to dispose of everything. I guess you could say it was like "the mark of Cain"
"Be gone you foul LP's and make way for tomorrows technology ". And look where we are now. Who would have thought it.
I took advantage of all the LP's I could afford at the time, as long as the contents were untouched. I really didn't care about the album covers. Every once so often I go to used LP shows (so to speak). But surprisingly, I rarely see any punched or cut album covers. I guess the practice wasn't as wide spread as some might think. I'm not certain what effect the "marks" might have on resale value. Frankly, I am only concerned about the content, and not the container. I don't think you will have to worry about any dealers punching holes in CD packaging, when they are finally on their way out. Just a thought